The objective of this study is to determine whether risk factors for cerebrovascular disease are associated with cognitive dysfunction in a cohort of 234 clinically stroke-free elderly subjects. The effects of hypertension, diabetes mellitus, cardiac disease, and elevated lipid levels will be investigated with reaction time tasks as well as standard neuropsychological testing. Blood assays will be used to define risk factor exposure and Magnetic Resonance Imaging studies will be performed on 75 subjects randomly selected from the full cohort to determine whether any of these individuals have experienced "silent" cerebral infarctions. Specifically, this study will attempt to determine: (1) whether exposure to specific risk factors for cerebrovascular disease is associated with cognitive dysfunction or decline; (2) whether the presence of "silent" cerebral lesions is associated with cognitive dysfunction or decline; (3) whether a highly sensitive, yet culture-fair, assessment technique can be developed for use in the investigation of the subtle effects of these risk factors. A combination of univariate and multivariate analytic techniques will be used to address each of these issues. The results of this study hold the potential for early recognition of cognitive dysfunction in the elderly, which may be the first sign of significant cerebrovascular disease, through the use of assessment techniques better suited to the examination of individuals at greatest risk of such dysfunction due to a higher frequency of risk factor exposure, those who are elderly, under-educated, and nonwhite. Finding a significant relationship between risk factors and cognitive function will have significant implications for the medical management of "normal" aging individuals. Intervention may be beneficial not only in reducing the incidence of clinical cerebral or cardiovascular disease, but may also prevent cognitive decline in certain individuals.